This application is for the continued support of a training program in Allergy and Clinical Immunology that is designed for postdoctoral medical and pediatric trainees. There is a double training faculty. Firstly, clinician-researchers from Pediatrics, the Department of Medicine in Allergy and Clinical Immunology, Rheumatology, Pulmonary, Gastroenterology, Dermatology, Infectious Diseases and Human Translational Immunology. Secondly, Mentors, who are basic scientists mainly from Yale's outstanding Department of Immunobiology faculty. Together, their expertise spans nearly all of the areas important to allergy, clinical immunology, and modern immunology; including: humoral, cellular, molecular, genetic, biochemical, antigen- processing/presenting, and signaling research. Some faculty are experts in Lyme disease, which was discovered at Yale by faculty in this training program. We continue with siRNA treatment of ticks to understand pathogenesis and develop vaccines. There is rigorous training in Allergy, and Clinical immunology, and some in Immunologic aspects of Rheumatology, Dermatology, Gastroenterology, Pulmonary, and ENT. The training faculty is well equipped with major instruments including: outstanding flow cytometry, oligonucleotide synthesizer, protein sequinator and access to array and deep cDNA sequencing (Illumina/Solexa). This is a small high quality training program, taking only one new fellow per year, with a large faculty emphasizing the need for at least of 3-5 years of laboratory research to prepare trainees for positions in research medicine, upon which we are focused. The faculty have a strong training record and collaborative research interactions. The fellows spend their first year in clinical activities. The second and third years entirely in a research project under an Immunobiology faculty mentor, while taking various immunobiology and clinical science courses, participating in weekly seminars and journal clubs, and regularly giving talks on their research, and immunologic/allergy subjects of interest. In summary, the program offers unique and very high quality training of outstanding candidates for future positions in academic medicine and pediatrics, and has been quite successful in this regard over more than 30 years of continuous funding.